Researchers use neuroimaging to study ESP
CAMBRIDGE, Mass., Jan. 3, 2008 -- Psychologists at Harvard University have developed a new method to study extrasensory perception that, they argue, can resolve the century-old debate over its existence. According to the authors, their study not only illustrates a new method for studying such phenomena, but also provides the strongest evidence yet obtained against the existence of extrasensory perception, or ESP.
The research was led by Samuel Moulton, a graduate student in the department of psychology in the Faculty of Arts and Sciences at Harvard University with Stephen Kosslyn, John Lindsley Professor of Psychology at Harvard and was published in the Jan. 2008 issue of the Journal of Cognitive Neuroscience. The scientists used brain scanning to test whether individuals have knowledge that cannot be explained through normal perceptual processing.
"If any ESP processes exist, then participants' brains should respond differently to ESP and non-ESP stimuli," explains Moulton. “Instead, results showed that participants’ brains responded identically to ESP and non-ESP stimuli, despite reacting strongly to differences in how emotional the stimuli were and showing subtle, stimulus-related effects.”
Nearly half of the adults in the United States believe in the existence of ESP, which includes telepathy (direct knowledge of another person's thoughts), clairvoyance (direct knowledge of remote events), and precognition (direct knowledge of the future). People commonly report unexplained knowledge of a loved one's death or a telephone caller's identity, for example, and attribute this knowledge to paranormal mental processing.
The U.S. government lent credence to such claims when it revealed that it had spent millions of dollars recruiting and training psychic spies during the Cold War. Furthermore, research studies have been reported that appear to support the existence of ESP, including an influential series of experiments analyzed by psychologist Daryl Bem of Cornell University. These studies, however, gave little insight into the mechanisms -- normal or paranormal -- that produced the anomalous results. Perhaps more telling, others failed to replicate these results.
To develop a better test of ESP, the authors decided to develop a new method, which directly addressed the presumed source of ESP: namely, the brain. They argue that because the brain enables perception and stores information -- even events people don't consciously perceive or information they can't consciously remember -- it can offer a much more comprehensive test for ESP than self-report or behavior.
"The brain shows a suppressed response to stimuli that a person has seen before, even when those stimuli were presented subliminally, so the person wasn't consciously aware of having seen them; furthermore, it shows an enhanced response to stimuli that a person is expecting," says Moulton. "Because knowledge and expectation bias brain activation, neuroimaging offers us a uniquely powerful test of subtle perceptual or cognitive processes."
To study whether or not ESP exists, Moulton and Kosslyn presented participants with two types of visual stimuli: ESP stimuli and non-ESP stimuli. These two types of stimuli were identical with one exception: ESP stimuli were not only presented visually, but also were presented telepathically, clairvoyantly, and precognitively to participants.
To present stimuli telepathically, the researchers showed the photographs to the participants' identical twin, relative, romantic partner, or friend, who was seated in another room. To present stimuli clairvoyantly, the researchers displayed the photographs on a distant computer screen. And to present stimuli precognitively, the researchers showed participants the photographs again in the future.
Does this conclusively prove that ESP does not exist" "No," says Moulton. "You cannot affirm the null hypothesis. But at the same time, some null results are stronger than others. This is the best evidence to date against the existence of ESP. Perhaps most important, this study offers scientists a new way to study ESP that avoids the pitfalls of past approaches."
http://www.thecrimson.com/article.aspx?ref=521471
Harvard psychologists have released a study that they say provides the most convincing evidence yet against the existence of extrasensory perception (ESP).
In a study published in this month’s issue of the Journal of Cognitive Neuroscience, graduate student Samuel T. Moulton ’01 and Psychology Professor Stephen M. Kosslyn used functional magnetic resonance imaging (fMRI) to assess whether individuals can have knowledge that does not come from normal perceptual processes. This focus on the brain sets their study apart from previous ESP research.
In the study, researchers tested three types of ESP: telepathy, clairvoyance, and precognition.
The procedure involved participants viewing sets of photographs while inside an fMRI scanner. Some of the pictures, designated “ESP stimuli,” were also presented to the subject via the different forms of ESP. Stimuli shown telepathically were presented simultaneously to another person—the subject’s relative, romantic partner or friend—in a separate location. Stimuli presented by clairvoyance, the ability to perceive distant things or events, were displayed on a computer located outside the subject’s field of vision. Finally, pictures presented through precognition, the ability to see into the future, were shown to subjects at a later time.
According to Moulton, if ESP existed, the brain would respond differently to pictures designated as ESP stimuli and non-ESP stimuli. Theoretically, pictures perceived through ESP should produce a pattern in the brain similar to ones produced when an individual sees a previously encountered stimulus.
Instead, Moulton found that participants responded identically to both stimuli types, resulting in the lack of a statistically significant difference that is referred to as a “null result.”
Moulton said null results have made previous ESP research difficult to interpret, but that he wanted to design an experiment that would give information independent of whether or not it produced null results.
“We didn’t find anything, but we didn’t find anything in an interesting way,” he said.
Moulton said he was initially inspired by research he conducted for his senior thesis, which demonstrated that brain activity is affected by previous exposure, even when this exposure is subconscious.
When asked why people believe in ESP, Moulton said he believes that cognitive biases can result in people interpreting events in a paranormal way.
“We’re hard-wired to see patterns in things that are probably random,” he said.
He acknowledged that while null results can never be used to conclusively prove that ESP does not exist, he was glad to have done his part toward settling the age-old debate.
Aside from getting published, Kosslyn said that the study also provided him with a Christmas present to give.
“I got my mom’s brain on the cover of the journal,” Moulton said. “She participated in the study, and then they put her scan on the cover, and that was her present.”
http://jocn.mitpress.org/cgi/content/abstract/20/1/182
Parapsychology is the scientific investigation of apparently paranormal mental phenomena (such as telepathy, i.e., "mind reading"), also known as psi. Despite widespread public belief in such phenomena and over 75 years of experimentation, there is no compelling evidence that psi exists. In the present study, functional magnetic resonance imaging (fMRI) was used in an effort to document the existence of psi. If psi exists, it occurs in the brain, and hence, assessing the brain directly should be more sensitive than using indirect behavioral methods (as have been used previously). To increase sensitivity, this experiment was designed to produce positive results if telepathy, clairvoyance (i.e., direct sensing of remote events), or precognition (i.e., knowing future events) exist. Moreover, the study included biologically or emotionally related participants (e.g., twins) and emotional stimuli in an effort to maximize experimental conditions that are purportedly conducive to psi. In spite of these characteristics of the study, psi stimuli and non-psi stimuli evoked indistinguishable neuronal responses—although differences in stimulus arousal values of the same stimuli had the expected effects on patterns of brain activation. These findings are the strongest evidence yet obtained against the existence of paranormal mental phenomena.
